Ribbon spools



July 23, 1968 H. F. E. DIXON RIBBON SPOOLS Filed July 29, 1966 INVENTOR. fi e/old FE Dz 'xor7 WM 44 AT OQNE 73' United States Patent Oflice 3,393,795 Patented July 23, 1968 ABSTRACT OF THE DISCLOSURE A two-piece duplicating ribbon spool molded from plastic comprising end members with telescopically frictionally-engaging hub sections, the inner hub section being tapered outwardly so as to expand the resilient slotted outer hub section when the spool is assembled to permit frictional engagement with a ribbon core present on the outer ,hub' section.

It is known to mold two-piece spools from plastics and several variations of such spools have met. with some form of commercial success. Two-piece spools can be molded in simple fashion, each piece being fairly similar to the other and being adapted to engage the other either permanently or removably. The present invention relates to spools of the latter type in which one section has a hub adapted to support the duplicating ribbon and the other section has a type of hub which is adapted to frictionally engage the hub of the first section and which is removable therefrom to permit replacement of the ribbon.

' While there are prior known two-piece ribbon spools having hub portions which frictionally engage each other, such spools have disadvantages which limit their utility. Such spools must be taken apart in order to replace the worn duplicating ribbon and it is a difficult task for the operator to remove the worn ribbon without dirtying the hands and fingernails. The spool sections must of necessity fit snugly and since the worn ribbon fills the spool cavity, there is no way to dislodge the spool sections without grasping their. outer circumferences with the fingers. Since the worn ribbon is present in proximity to theseouter circumferences, the fingers get dirty.

Another important disadvantage of such known spools is due to the fact that the core on which the duplicating ribbon is mounted must of necessity fit snugly on the hub of one section of the ribbon spool and is also diflicult to remove without soiling the fingers and unravelling the ribbon. The latter problem is most important in cases where the ribbon is not worn but is merely being temporarily replaced with a ribbon of another-type or color.

It is the main object of the present invention to provide a two-piece ribbon spool which does not have the aforementioned disadvantages and which may be taken apart, dislodged from a worn ribbon, filled with a new ribbon and reassembled without the necessity of the hands making contact with either ribbon.

It is another object of this invention to provide a twopiece ribbon spool onto which a duplicating ribbon may be locked and wound without the necessity of disassembling the spool, thereby avoiding the necessity of using a separateribbon core and the necessity of prolonged manual contact with the ribbon to attach it to the hub of the spool.

These and other objects and advantages of the present invention will be clear to those skilled in the art in the light of the following disclosure including the drawing, in which: i

FIGURE 1 is an inside face view of the outer end member of the two-piece ribbon spools of the present invention.

FIG. 2 is an inside face view of the inner end member of the present two-piece ribbon spools.

FIG. 3 is a cross-sectional side view of the assembled ribbon spools of the present invention.

FIG. 4 is a face view of the present assembled ribbon spools.

As shown in the drawing, the present ribbon spools consist of two circular end members or flanges. The outer flange 10 is shown in FIG. 1 and comprises a flat radial surface 11 having a central outer hub section 13 projecting therefrom. The radial surface 11 and hub section 13 are provided with a continuous slot 12. The outer flange is molded of synthetic resilient plastic material and therefore the circumference of the central hub section 13 is variable to a slight extent. Pressure applied against the inner circumference of hub section 13 Causes the slot 12 to open slightly and the circumference of hub section 13 to increase slightly, while pressure applied against the outer circumference of hub section 13 or against the outer circumference of flat radial surface 11 causes the slot 12 to close slightly and the circumference of hub section 13 to become slightly reduced. In such cases, however, the memory of the plastic material of the outer flange 19 attempts to return the flange 10 and its central hub section 13 to its originally molded circumference so that the flange 10 is continuously under stress when pressures distort the original circumference.

The inner flange 20 is shown in FIG. 2 and comprises a flat radial surface 21 having substantially the same outer circumference as outer flange 10. The inner flange 20 has a central sleeve 23 adapted to support the spool on the ribbon winding shaft of a typewriter or other duplicating machine. Spaced outwardly from section 23 is a substantially rigid inner hub section comprising segmented hub sections 22 which project outwardly to substantially the same distance as core section 23 and which have a maximum segmented circumference which is slightly greater than the inner circumference of hub section 13 of outer flange 10. Segmented hub sections 22 have their outer surfaces slightly tapered from the flat radial surface 21 so that their maximum segmented circumference is adjacent the flat radial surface 21 and the segmented circumference gradually decreases until at the outer edge adjacent the tips of the segmented hub sections 22, the outer segmented circumference is slightly smaller than the inner circumference of hub section 13 of outer flange 10- As shown by FIG. 3, the flanges 10 and 20 telescopically frictionally engage each other to form the present spools. The inner circumference of outer hub section 13 is greater than the segmented circumference at the extremities of segmented hub sections 22 so that initial alignment of the end sections is simple. As the flanges are compressed into final position where the edge of hub 13 makes contact with flat radial surface 21, the circumference of hub 13 becomes slightly enlarged due to the pressure exerted by the tapered segmented hub sections, the segmented circumference of which is greater adjacent flat radial surface 11 than the inner circumference of hub section 13. Due to the memory of the plastic of the outer flange, the two flanges are strongly frictionally engaged.

FIG. 4 shows the spool of FIG. 3 viewed against the outer flange 10. Due to the pressure exerted against the inner circumference of hub section 13 by segmented hub sections 22, the circumference of hub section 13 and the width of the continuous slot 12 are slightly greater than in relaxed condition as shown in FIG. 1. FIG. 4 also demonstrates one of the segmented hub sections 22 of the inner end section in position, shown as 24, engaging the inner side of the slot in hub section 13. Since the width of the segmented hub sections is greater than the width of slot 12, then the inner hub section can be rotated within outer hub section 13 of the outer flange so that any one of the segmented hub sections frictionally seals slot 12 when in position indicated as 24. This feature is important in cases where the ribbon is to be wound directly onto the outer circumference of hub section 13. To initially engage the end of the ribbon, the inner flange 20 is rotated within hub 13 until the slot 12 is open and aligned with the slot comprising the separation between two segmented hub sections 22. The ribbon end is inserted through the slot in the outer hub section 13 and through the slot comprising the separation between sections 22 which is facilitated by the fact that the slot 12 also extends through the flat radial section 10. Then the inner flange 20 is rotated so that one of the segmented hub sections 22 comes at least to the position indicated at 24 to engage the end of the ribbon between its upper surface and the under surface of hub section 13. This locks the ribbon end in position so that the rest of the ribbon can now be wound on the spool without the end pulling loose. Similarly when the ribbon is to be replaced, this may also be accomplished without taking the spool sections apart by merely rotating the flanges to unlock the old ribbon and to lock in the new ribbon.

The most important utility for the present ribbon spools is in connection with film-base typewriter ribbons which are initially wound on their own disposable core. It has been difficult to provide spools for such ribbons because the inner surface of the ribbon core must fit tightly over the outer circumference of the hub of the spool so that slippage is avoided. It is exceptionally diflicult to maintain such a close tolerance so that in many cases the hub is so small that slippage occurs or so large that the ribbon core cannot be slipped over the hub.

However, because of the variable circumference of the hub section 13 of the present ribbon spools, the aforementioned problem is solved. The core of the ribbon can be easily slipped over the hub 13 of the outer flange by compressing the outer circumference of radial surface 11 to narrow opening 12 and reduce the circumference of hub section 13. This can be accomplished without touching the ribbon or its core with the hands. The inner flange 20 is then pressed into position whereby the outer segmented circumference of segmented hub sections 22 frictionally engages the inner circumference of hub section 13 more tightly as the flanges are brought closer together. This pressure also looks the upper surface of hub 13 against the inner surface of the ribbon core so that slippage is prevented. This step can also be accomplished without manually touching the ribbon or its core.

Similarly, the ribbon can be removed from the present spools and replaced with a new ribbon without the necessity of touching the ribbon. This is accomplished by placing the palms of the hands against the exposed sides of the flat radial surfaces 11 and 21 and rotating the sides in opposite directions. This causes the inner flange 20 to separate gradually from the outer flange and to loosen so that it can be easily removed with the fingers. This separation and loosening is due to the taper of the segmented hub sections 22 which causes the stressed hub section 13 of the outer flange to slip and to dislodge from the segmented hub sections.

Also the previously difficult problem of removing the worn ribbon and its core from the hub of the ribbon spool is easily accomplished with the present ribbon spools without the necessity of touching the ribbon or its core with the fingers. When the inner flange has been turned and slipped off the outer flange 10, the circumference of hub section 13 gradually decreases due to the memory of the plastic from which it is molded and due also to the pressure exerted by the tight-fitting ribbon spool. To further decrease this circumference to a point at which the ribbon core easily slips off hub section 13, one has merely 4' to apply finger pressures against the outer circumference of flat radial surface section 11 to cause the width of continuous slot 12 to decrease.

The present ribbon spools may be molded from any number of synthetic plastic materials known for their strength and resiliency. Among the preferred materials are nylon, polyethylene and polypropylene (preferably oriented), vinyl polymers, polyamides, polyesters, and the like. i

Variations and-modifications may be made within the scope of the claims and portions of the improvements may be used without others.

I claim:

1. A spool for duplicating ribbons capable of cooperating with a ribbon-winding shaft and also capable of selectively frictionally attaching a ribbon end thereto and, in the alternative, of frictionally mounting a ribbon core thereon comprising a first flange and a second flange each having a central cylindrical hub section adapted to frictionally telescopically engage the other, the hub section of the first flange being the outer hub section which fits the hub section of the second flange which is the inner hub section, each flange extending radially outwardly from its hub section to form a ribbon-retaining wall, the first flange being resiliently flexible under the elfects of radial forces and having a slot which extends through the hub section and the ribbon-retaining wall to the periphery thereof whereby the circumference of the outer hub section is subject to increase or decrease under the effects of radial forces, and the inner hub section being substantially rigid against the eflects of radial forces, having a segmented circumference and comprising a plurality of taperedhub segments sufficiently spaced apart to admit a ribbon end therebetween, each said segment having a circumferential width greater than the width of the said slot in the said outer hub section, said inner hub section having an outer circumference adjacent its wall section which is slightly larger than the normal inner circumference of the outer hub and which gradually decreases with the taper of said hub segments towards its outer edge at which it is slightly smaller than the normal inner circumference of the outer hub, whereby as the flanges are pressed into assembled position the inner hub section easily enters the outer hub and gradually tightly frictionally engages and expands the outer hub, the flanges being easily disengaged by relatively rotating them whereby the pressure exerted by the outer hub in contracting forces the tapered hubsegments to slip from tight frictional engagement with the outer hub section and permits separation of the flanges, and a central sleeve attached to said second flange and being disposed internally of said hub segments and configured to mate with a ribborvwinding shaft.

2. A spool according to claim 1 in which the flanges are formed from synthetic plastic material.

3. A spool according to claim 2 in which the flanges are formed from polyethylene.

References Cited UNITED STATES PATENTS 2,930,470 3/1960 Roller et al. 197151 3,152,678 10/1964 Hunt 197-151 3,323,743 6/ 1967 Landgraf. 1,013,882 1/1912 Lasker 24274.2 1,578,231 3/1926 Deses et al. 242-74.1 2,652,918 9/1953 Lippert 197-175 2,974,892 3/ 1961 Geloso 24274 X 3,145,823 8/1964 Spradlin 197l75 3,195,828 7/ 1965 Kuckhoff et a1 242---74.1

FOREIGN PATENTS 681,482 9/1939 Germany.

ROBERT E. PULFREY, Primary Examiner. E. T. WRIGHT, Assistant Examiner. 

